Refrigerating apparatus



J. SMILACK REFRIGERATING APPARATUS Filed Oct. 31, 1934 Feb. 18, 1936.

INVENTOR. Leos Sal/Lack.

' I BY ms ATTORNEYJ.

acts as an insulator.

done manually, but recently automatic devices.

Patented Feb. 18, 1936 UNITED STATES 2,031,550 REFRIG RA'rmG APPARATUS Jacob Smilack, Dayton, Ohio, assignor to General Motors Corporation, Dayton; Ohio, a corporation of Delaware Application October 31, 1934, Serial No. 750,840

9Claims.

This invention relates to refrigerating apparatus and more particularly to a method of and apparatus for automatically disposing of moisture and water dripping from the cooling unit or evaporator of a refrigerating apparatus.

Mechanical refrigerators and room cooling apparatus, whether of the absorption or compression type, operating as they do to maintain a temperature in the evaporator below the temperature of the air being cooled by the evaporator act to a certain extent as driers. In other words, they extract water or moisture from the air adapted to flow thereover within the cabinet, the amount of moisture extracted depending to a large extent upon the temperature of the evaporator. If the temperature of the evaporator is above 32' F. as in room cooling apparatus, then the moisture collecting on the evaporator does not freeze but runs oil or drains into some sort of receptacle located either within or without the cabinet. If the temperature of the evaporator is maintained below 32 F. as in refrigerators of the household type, then the moisture extracted from the air freezes on walls of the evaporator in the form of frost. Eveninthislatter caseitisnecessaryto periodically dispose of the frost or ice since it Heretofore this has been such as that shown in the King Patent 1,658,340 and the Raney Patents 1,877,967 and 1,867,711, have been suggested for performing this function automatically. Thls'is done by periodically increasing the temperature of the cooling unit above the freezing point so that the frost melts from the cooling unit. The drip-water resulting from melting fresh from walls of the cooling unit has been customarily collected in some sort'of receptacle located within or without the cabinet. If this receptacle is not emptied at the proper time, it is likely to overflow and cause considerable trouble and dissatisfaction.

In the application of Richard S. Gaugler, Serial No. 672,916, filed May 26, 1933, there is disclosed an electrical means which will dispose of the dripwater from any cooling means automatically. In the application referred to, there is .disclosed a plurality of spaced apart plate-like electrodes dis posed in a drip catching receptable, which electrodes are connected with an electrical power circult. and upon being bridged by a body of dripwater accumulating in the receptacle electric energy flows from one electrode to the other through the water, thus heating the water, due to resistance to the flow of current therethrough. and causing evaporation thereof. While the de- ,above referred to at best causes evaporation of the drip-water only very slowly and if adjusted or constructed to cause rapid evaporation of the water from the receptacle, sufl'icient current' passes through the water .to each electrode to cause a short circuit of such intensity that fuses in the electrical circuit are likely to be blown.

It is therefore an object of my invention to provide an improved electrical means which will. dispose of the drip-water from a cooling element automatically and more rapidly than has heretofore been accomplished without requiring the users attention.

It is a more specific object of my invention to utilize the small amount of electric current ordinarily flowing through water between two electrodes in a drip collecting receptacle of a refrigerating apparatus to complete another electrical circuit leading to an electrical heater, mounted in thermal association with but isolated from the body of drip-water in the receptacle, for energizing the heating element and causing the body of the water to be rapidly vaporized or evaporated from the receptacle.

It is a further object of my invention to provide an electrical water evaporating device whose effectiveness is initiated by the accumulation of a predetermined amount of water in a receptacle and which remains effective for a considerable length of time after the level of water is reduced far below the level thereof which initiates the eifectiveness of the device to insure evaporation of a large body of water each time the device is rendered effective. a

In carrying out the foregoing objects, it is a still further object to provide an improved electrical nieans that will be eificient in its function of rapidly disposing of drip-water from a cooling unit of a refrigerating apparatus and which will be compact and of low manufacturing cost.

Further objects and advantages of the present invention will be apparent from the following description, reference being bad to the accomp'anying drawing, wherein -a preferred form of the present invention is clearly shown.

In the drawing:

Fig. l is a front elevational view of a mechanical refrigerator having y invention embodied therein;

Fig. 2 is an enlarged fragmentary sectional view showing a drip-water evaporating means constructed in accordance with my invention and showing the electrical circuit ditically connected therewith: and

Fig. 3 is a sectional view of the lead-in plug carrying the electrodes employed in my device.

Referring to the drawing, for the purpose of illustrating my invention, 1 haveshown. in Fig. 1 thereof a refrigerator cabinet 20 having a food compartment 2i and a machinery compartment 22. Thefood compartment 2i is surrounded and formed by insulated walls 23 and is cooled by means which includes an evaporator or cooling unit 24 and a refrigerant liquefying means or unit 25. The refrigerant liquefying unit 25 comprises a compressor 26 for compressing the refrige'rant and for forwarding the compressed refrigerant to the condenser 21 where the refri erant is liquefied and collected in a receiver 28. From the receiver 28 liquid refrigerant is forwarded under pressure, through a suitable conduit 29 under the control of a suitable automatic expansion valve 30, to the cooling unit 24. The liquid refrigerant within the cooling unit 24 evaporates because of the absorption of heat from the air within the food compartment 2| and is returned to the compressor 26 through the return conduit 3 l. The compressor 25 is driven by .an' electric motor 32 through suitable connections such as the pulley and belt means 33.-

The operation of the electric motor 32 and the compressor 25 is under the control of an automatic switch 34 which may be of any suitable type such as that shown in the King Patent 1,658,340 or that shown in one of the Raney Patents 1,877,967 and 1,867,711. This automatic switch 34 is under the control of a thermostatic bulb 35 which may be mounted in contact with.

any desired portion of the cooling unit '24. The automatic switch 34 is connected into electrical supply conductors 31 to open and close the electric motor circuit at suitable intervals to P p erly control the temperature of the coolin unit 24.

The automatic switch 34 normally controls the temperature of the cooling unit so that its temperature is maintained below water freezing temperatures. This causes frost to collect on walls of the cooling unit and the automatic switch 34 is ofthe type to periodically cause the temperature of the coolingunit 24 to increase above water freezing temperature so that frost accumulated on the walls of the cooling unit will melt therefrom. Instead of this type of control, the switch 'maov so control the cooling unit temperature, as

frost from walls of the cooling unit drips from the cooling unit or evaporator 24 and flows into a tray or into a trough or cutter 40 as herein disclosed as being formed in the bottom of the lining member of the food compartment and lo catcd directly beneath the evaporator 24. A tube 4| which passes through the bottom of the insulated wall of the food compartment into the machine compartment 22 is connected with the tray or with the lowermost portion of the trough or cutter 40. The lower end of tube 4i extends to a point spaced slightly from the bottom wall of a cup-shaped member 42 to form in coopera tion with the drlpwater a liquid trap .or seal at the end of tube 4| to prevent vapor or air from ascending into the food compartment. The cup member 42 is secured to the underside of the bottom'wall of the food compartment by screws or bolts 43 and is provided with a plurality of openlugs 44 for permitting drip-water to overflow therefrom. Surrounding the cup member 42 is a. small generally cylindrical receptacle or tank 45. Receptacle or tank 45 has a flange 4G abutting and secured to the bottom wall of the insulated food compartment by screws or bolts 41. A threaded opening 48 is provided in the lower portion of the side wall of tank 45 and is closed by abakelite or porcelain plug 49 and a gaskettfl. A plurality of openings 5| are provided around the upper part of tank 45 for a purpose to be hereinafter described. The insulating plug 49 has two electrodes 52 and 53 preferably molded therein in spaced apart relation. The electrodes 52 and 53' are sealed in the plug 49 and extend entirely therethrough so as to have the inner ends thereof exposed to 'the interior of the tank 45 and so as to have the outer ends thereof adapted to receive an electrical connection. Thermally associated with or secured to the bottom wall of tank 45. in any suitable manner, there is located 2 an electrical heating unit 55 containing a resistance winding 56 suitably insulated and having a connection with each of the lead-in terminals 51 and 58. It is to be understood that the receptacle .63 and 64 secured to the underside of thebottom wall of the insulated food compartment. The resistance or heater wire Si is spaced slightly from the thermostat 52 and has terminal connections 65 and 66. The terminal connection 65 of heater Si is connected with and includes a terminal for the conduction of current through the bimetal thermostat 62. The thermostat 52 carries at its free or movable end a contact 51 adapted to engage a contact 68 carried by a terminal 69 moimted in the block 64. It is to be understood that the switch unit just described may be located in a boxer the-like enclosure and mounted wherever desired.

The electrical circuit connected in parallel with the power supply conductors 31 of switch 34 and motor 32 and leading to the electrode 52, heater 55, thermostat 62 and heater 5i will now be described. ing wherein this electrical circuit is illustrated ditically, there is a wire H which is connected with one of the power supply conductors 31 (see Fig. 1) and which leads to the terminal 12 attached to the electrode 53. A branch wire 13 connects the terminal 58 of heater 55 and resistance wire 55 located therein with the wire H A wire [4, connected to the other of the power supply conductors 2! (see Fig. '1) of the circuit to the motor and switch, is attached to the terminal 65 leading to heatertl and thermostat G2. The terminal 65 of the heater 5 l for thermoa stat 52, is connected by a wire 15 to a terminal 16 attached to the electrode 52. A wire Tl connects the terminal 59 with the terminal 51 of the heater 55.

The electrode 53 is connected at its binding post terminal 12 by wire ll with the source of Referring to Fig. 2 of the draw-' electrical supply at all times and the electrode 52 is likewise connected at its binding post terminal 16 with the source of electrical supply through wire [5,- terminal 66, thermostat heater 6|, terminal 55, and wire I4. This causes the electrodes to be charged with electrical energy at all times and maintains an electrical potential between them. However, since these electrodes are insulated from one another there is ordinarily no current flowing between them and no electric energy is used. In practicing my invention it will be understood that the heater wire 6| for the thermostat switch is preferably of greater resistance to flow of electric energy than the drip-water in receptacle 4550 that when the electrodes 52 and 53 are bridged by the water the amount of current passing through wire 6| is sufficient to cause heating of the wire for effecting the thermostat 62.

When moisture or water drips from the cooling element or evaporator 24 for any reason whatsoever, such as during the defrosting period automatically initiated as described by the switch 34, thismoisture or drip-water is caught in the trough or cutter 40 and is conducted by conduit or tube 4| into the sealing cup 42 from which it overflows through the openings 44 into the receptacle or tank 45. The drip-water collects in the lower portion of tank 45 and when a suflicient amount has been collected, the level of the water rises so that it contacts both of the electrodes 52 and 53. The drip-water upon contacting both electrodes causes a small amount of electric energy to flow from one electrode to the other through the water. The arrangement is such that the amount of current flowing through the water is sufllciently to cause heating of the resistance wire 6| but preferably no appreciable heating of the water bridging the electrodes 52 and 53. The amount of electric energy or current capable of being conducted from one electrode to the other through the water being in accordance with this invention suflicient to cause the circuit connecting the electrodes with the source of electric supply to be closed. Closing of this circuit through wires TI, 74, and 15 causes heater 5| of thermostat 62 to be energized, thus generating heat and radiating same against or upon the bimetal element 62. Heating of the bimetal element 62 causes its free or contact carrying end to move away from the heater wire 6! and toward the terminal 69. The contact 61, carried on the free end of the thermostat element 62, engages the contact 68 of terminal 69, thus completing or closing the electric circuit leading to the secondary heater 55. the disclosure and description thereof, that the circuit to the heater just described is made through good metallic conducting elements entirely independent of the water connection between the electrodes 52 and 53 and the resistance wire 6|. Therefore electric energy is readily conducted to the resistance element 56 of heater 55 without passing through or being impeded by other resistance means or elements in the circuit. The unit 55 and its resistance element 56 may be of any suitable well-known construction and arrangement as to generate considerable heat rapidly and are associated with receptacle 45 in such manner as to transfer this heat to water in the receptacle. Other provisions obviously within the realm of my invention can be made, such, for

example, as a secondary electric circuit of low voltage, to insure that very little electrical energy will pass through the water, when the water It will be understood from bridges the electrodes 52 and 53, to prevent blowing of fuses in the circuit. Thus provision to insure that the thermostat heater 6| generates only a small amount of heat suflicient to cause operation or movement of the bimetal member 62 as compared to the amount of heat generated or produced by the heating resistance element 56 are obvious. Consequently, when the heater 55 is rendered effective, drip-water in receptacle 45 is rapidly heated, without directly contacting the heating element, and is caused to vaporize. The vapor resulting from evaporation of water in receptacle 45 rises and flows outwardly of the receptacle through the openings 5| and is carried away by air, circulated by the refrigerating mechanism, sweeping over or around the receptacle.

When the contacts 61 and 68 are closed, to conduct electric energy directly through good metallic conductors, to the secondary heater 55, the circuit betweenthe electrodes 52 and 53 through wires H and I5, terminal 66, heater wire 6|, terminal 65, and wire 14, remains closed as long as there is suflicient water in the receptacle 45 to bridge or contact both electrodes. As soon as sufllcient water has been evaporated or vaporized from receptacle or tank 45 to cause the level of the drip-water to be lowered or to fall below electrode 52, the electrical circuit leading to heater wire 6|, through the electrodes 52 and 53 from wire H and wire 15, will be broken, thus deenergizing the heater 6|. Therefore, resistance wire 6| ceases to generate heat and the bimetal thermostat 62 begins to cool and after a predetermined period of time, according to the arrangement and location of the thermostat, the bimetal member 62 will move back into its normal position adjacent the heater wire 6|. This movement of bimetal thermostat 62 is thus delayed for a predetermined length of time, depending on the time required to cool same, and the contacts 51 and 68 remain closed for a period of time after the circuit to the thermostat heater 6| has been broken by the lowering of the water level below electrode-52. The heater 55 is thereby caused to continue heating of the receptacle 45 until the contacts 61- and 68 are separated bythe cooling and consequent movement of the thermostat 62. The prolonged breaking of the circuit to the heater 55 as accomplished in the manner described is desirable for the reason, that it insures that substantially all of the drip-water contained in tank or receptacle 45 will be evaporated therefrom. Ordinarily a considerable length of time will therefore elapse before the level of drip- Water in the receptacle 45 attains a height sufficient to again energize the electrical vaporizing system and operations of the thermostat 62 are thus minimized. Thela'pse of time between operations of energizing my electrical vaporizing system can be predetermined to suit the required installation by constructing the tank 45 so that the distance between the electrode 52 and the bottom of the tank or receptacle will hold the desired amount of water in accordance with the prolonged cooling and consequently movement of thermostat 62.

It will be seen that I have provided an extremely efiective evaporating means for removing the drip-water from cooling elements of refrigerating systems. I have provided an improved means, over that disclosed in the Gaugler application referred to, in that my improved evaporating means will insure positive removal of a large amount of water thus being eificiently applicable to room cooling or the like installations wherein drip-water flows from the cooling element or evaporator almost continuously. My improved evaporating means eliminates the troubles, enumerated at the beginning of this specification, which have heretofore been incidental to the operation of mechanically cooled refrigerators.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A refrigerating apparatus including a cabinet, means for cooling air adapted to flow there over mounted in said cabinet, said cooling means having moisture dripping therefrom, means for collecting the drip-water from said cooling means, an electrical heating element for causing evaporation and removal of drip-water from said collecting means, means responsive to a predetermined accumulation of' drip-water in said collecting means for initiating effectiveness of said heating element, and a portion of said last named means being constructed and arranged to cause the effectiveness of said heating element to be prolonged for a predetermined period of time after the drip-water in said collecting means has been diminished beyond the predetermined accumulation thereof for rendering the initiating means effective.

2. A refrigerating apparatus including a cabinet, means for cooling air adapted to flow thereover mounted in said cabinet, said cooling means having moisture dripping therefrom, means for collecting the drip-water from said cooling means, an electrical heating element disposed exteriorly of and in intimate thermal association with said collecting means for causing evaporation and removal of drip-water therefrom, and means responsive to a predetermined accumulation of drip-water in said collecting means for rendering said heating element effective.

3. A refrigerating apparatus including a cabinet, means for cooling air adapted to flow thereover mounted in said cabinet, said cooling means having moisture dripping therefrom, means for collecting the drip-water from said cooling means, an electrical heating element disposed exteriorly of and in intimate thermal association with said collecting means for causing evaporation and removal of drip-water therefrom, means responsive to a predetermined accumulation of drip-water in said collecting means for initiating effectiveness of said heating element, and a portion of said last named means being constructed and arranged to cause the effectiveness of said heating element to be prolonged for a predetermined period of time after the drip-water in said collecting means has been diminished beyond the predetermined accumulation thereof for rendering the initiating means effective.

4. A refrigerating apparatus including a cabinet, means for cooling air adapted to flow thereover mounted in said cabinet, said cooling means having moisture dripping therefrom, means for collecting the drip-water from said cooling means, an electrical heating element for causing evaporation and removal of drip-water from said collecting means, a pair of spaced apart electrodes disposed within said collecting means and insulated from'one another, an electric circuit connected to a source of electric supply and to said 1 electrodes, an electric circuit connected to a source of electric supply and to said heating element, a switch disposed in the circuit leading to said heating element and normally being in open position, means in said circuit leading to said electrodes for closing said switch to render said heating element effective, and said switch closing means being rendered effective in response to a predetermined accumulation of drip-water in said drip collecting means.

5. A refrigerating apparatus including a cabinet, means for cooling air adapted to flow thereover mounted in said cabinet, said cooling means having moisture dripping therefrom, means for collecting the drip-water from said cooling means, an electrical heating element for causing evaporation and removal of drip-water from said collecting means, a pair of spaced apart electrodes disposed within said collecting means and insulated from one another, an electric circuit connected to a source of electric supply and to said electrodes, an electric circuit connected to a source of electric supply and to said heating element, a switch disposed in the circuit leading to said heating element and normally being in open position, means in said circuit leading to said electrodes for closing said switch' to render said heating element effective, said switch closing means being rendered effective in response to a predetermined accumulation of drip-water in said drip collecting means, and said switch being constructed and arrangedto cause the elfectiveness of said heating element to be prolonged for a predetermined period of time after the dripwater in said collecting means has been diminished beyond the predetermined accumulation thereof for rendering saidswitch closing means effective.

6. A refrigerating apparatus including a cabi net, means for cooling air adapted to flow thereover mounted in said cabinet, said cooling means having moisture dripping therefrom, means for collecting the drip-water from said cooling means, an electrical heating element for causing evaporation and removal of drip-water from said collecting means, a pair of spaced apart electrodes disposed within said collecting means and insulated from one another, an electric circuit connected to a source of electric supply and to said electrodes, an electric circuit connected to a source of electric supply and to said heating element, a bi-metal thermostatic switch disposed in the circuit leading to said heating element and normally being in open position, an electrical resistance unit disposed in said circuit leading to said electrodes, said resistance unit being located adjacent said bi-metal thermostatic switch and adapted to heat same to cause closing thereof for rendering said heating element effective, and said switch closing resistance unit being rendered effective in response to a predetermined accumulation of drip-water in said drip collecting means.

'7. A refrigerating apparatus comprising in combination, means for cooling air adapted to flow thereover, said cooling means being adapted to collect moisture thereon and to have moisture dripping therefrom, means for catching the drip water from said cooling means, and heating means for causing evaporation of drip water from said catching means, said heating means being disposed exteriorly of and in intimate thermal association with said catching means and being normally ineffective and rendered effective automatically in response to a predetermined accumulation of drip water in said catching means.

8.'A refrigerating apparatus comprising in combination, means for cooling air adapted to flow thereover, said cooling means being adapted to collect moisture thereon and to have moisture dripping therefrom, means for catching the drip water from said cooling means, and heating means for causing evaporation of drip water from said catching means, said heating means being normally ineifective and rendered efiective automatically in response to a predetermined accumulation of drip water in said catching means, and means for prolonging the effectiveness of said heating, means for a period of time after the drip water in said catching means has been diminished beyond a predetermined accumulation thereof by said heating means.

9. A refrigerating apparatus comprising in combination, means for cooling air adapted to flow thereover, said cooling means being adapted to collect moisture thereon and to have moisture dripping therefrom, means for catching the drip from said cooling means, and heating means for causing evaporation of drip water from said catching means, said heating means being disposed exteriorly of and in intimate thermal association with said catching means and being normally inefiective and rendered effective automatically in response to a predetermined accumulation of drip water in said catching means, and means for prolonging the effectiveness of said heating means for a period of time after the drip water in said catching means has been diminished beyond apredetermined accumulation thereof by said heating means.

' JACOB SMILACK. 

